The invention is based on a method and apparatus for making a butt seam having a cover strip on a tube of multi-layer packaging material. In a method of this kind, known for instance from German Offenlegungsschrift No. 26 53 753, the long edges of a sheet of packaging material are placed together and then, abutting one another, pass through an alternating electrical field of an induction coil to apply a cover strip along the seam. In this method, it happens again and again that the edges of the metal inlay embedded between nonconductive layers will come into physical contact with one another at various locations, especially where there are protruding cut corners. At these locations, because of the alternating electrical fields, arcing can occur, in the form of sparks, which burn holes especially in the thermoplastic protecting layer resting on the metal inlay. This phenomenon in the area of the longitudinal seam also occurs if a lid is welded or heat-sealed by an induced alternating electrical field onto a tubular piece of packaging material embodied in this way and manufactured by the above-described method. In a package of this kind which contains liquid, the liquid may leak through at the burned-through locations, which are hardly visible from the outside, and premeate the supporting layer of the packaging material, which may for instance be of cardboard, and increase the size such as ballooning if the package is stored for a period of time. If the burned holes are large enough, the liquid can even escape to the outside. Packaging container leaks of this kind are highly undesirable, however, because not only do they make the defective package itself unsalable, but other packages that may be joined to it in a pack are soiled as well.